000 AGXX40 KNHC 200808 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 355 AM EDT THU MAY 20 2010 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W GULF OF MEXICO... LATEST PRELIMINARY SURFACE SYNOPTIC ANALYSIS VALID 0600 UTC HIGHLIGHTS A WEAK RIDGE EXTENDING OVER ALONG 27N E OF ABOUT 92W ...WHILE A SURFACE TROUGH EXTENDS FROM NW CUBS SE ACROSS THE YUCATAN PENINSULA. LATEST SATELLITE IMAGERY SHOWS A WEAK 1009 MB LOW ALONG THE TROUGH NEAR NW BELIZE. LATEST AND RECENT BUOY AND OFFSHORE PLATFORM OBSERVATIONS SHOW SE-S WINDS 10-15 KT ACROSS THE AREA WITH THE EXCEPTION OF THE NE PORTION WHERE WINDS ARE LIGHT AND VARIABLE AND IN THE FAR SE WATERS WHERE OUTFLOW FROM SCATTERED TSTM ACTIVITY IN THE YUCATAN CHANNEL IS ELEVATING SE WINDS TO 10-15 KT. OBSERVED SEASTATE AS REPORTED BY BUOY AND SHIP OBSERVATIONS SHOW RELATIVELY LOW SEAS WITH RANGES FROM 1-2 FT ACROSS ALL OF THE GULF...EXCEPT 3-5 FT IN THE FAR NW SECTION OF THE NW ZONE AND IN THE FAR SOUTHERN WATERS OF THE MIDDLE SECTION TO INCLUDE THE YUCATAN CHANNEL. THIS IS IN VERY GOOD AGREEMENT WITH GUIDANCE FROM THE 0000 UTC WAVEWATCH MODEL GUIDANCE...SO WILL ADHERE TO GUIDANCE FOR THIS FORECAST PACKAGE. LATEST MODEL GUIDANCE SHOWS THAT THESE CONDITIONS WILL CHANGE VERY LITTLE OVERALL THROUGH DAY 5 (MON) WITH ONLY FORESEEABLE CHANGES EXPECTED IN THE SE...AND FAR SOUTHERN WATERS OF THE GULF BEGINNING THIS AFTERNOON WHERE MODELS...GFS BEING THE MOST AGGRESSIVE...INDICATE THAT A WIND SURGE MOVES FROM THE NW CARIBBEAN SEA W ACROSS THESE WATERS BEFORE DAMPENING OUT ON SUN. THIS SURGE APPEARS THAT IT WILL ATTRIBUTED TO THE LOW AND TROUGH MENTIONED ABOVE IN FIRST PARAGRAPH. WITH THIS FEATURE...EXPECT SEAS TO REMAIN IN THE RANGE OF 4-6 FT IN THE FAR SE AND SOUTHERN GULF THROUGH MON AS A SE SWELL MIGRATES FROM THE CARIBBEAN INTO THESE WATERS. RETURN SLY FLOW IN THE 15-20 KT RANGE OVER THE FAR WESTERN WATERS DUE TO LOW PRES DEEPENING OVER THE SOUTHERN PLAINS AS IT INTERACTS WITH RIDGING TO THE E OVER THE NORTHERN GULF WILL PERSIST THROUGH TONIGHT...THEN DIMINISH ON FRI...AND INCREASE ONCE AGAIN LATE SAT THROUGH MON WITH SHORT DECREASING TRENDS THROUGH THIS PERIOD. SW N ATLC... A RIDGE IS ANALYZED ROUGHLY ALONG 27N E OF THE BAHAMAS. A TROUGH IS ANALYZED ALONG 79W S OF 26N. SLIGHT TIGHTENING OF THE PRES GRADIENT ON THE SOUTHERN PERIPHERY OF THE RIDGE IS AGAIN ALLOWING FOR A SMALL POCKET OF E-SE 15-20 KT WINDS CONFINED TO THE S OF 21N E OF THE BAHAMAS AS CONFIRMED IN AN ASCAT PASS FROM 0132 UTC LAST NIGHT. OVER THE REMAINDER OF THE AREA WINDS ARE LIGHTER E-SE S OF 26N...AND SE-S N OF 26N. SEAS RANGE FROM 2-4 FT N OF 26N W OF 71W...TO 3-5 FT N OF 26N E OF 71W...5-7 FT S OF 21N E OF BAHAMAS AND 1-3 FT W OF BAHAMAS. AN EXTENSIVE AREA OF NUMEROUS SHOWERS AND TSTMS AS OBSERVED ON SATELLITE AND ON NW DOPPLER RADAR IMAGERY IS SPREADING FROM W TO E N AND W OF 75W. THIS IS IN ASSOCIATION WITH A MID/UPPER TROUGH RAPIDLY ADVANCING EASTWARD OVER THE EASTERN GULF OF MEXICO. EXPECT GUSTY WINDS AND BUILDING SEAS IN AND NEAR THIS ACTIVITY AS IT SPREADS FURTHER E ACROSS THE BAHAMAS ISLANDS ...STRAITS OF FLORIDA AND WATERS BETWEEN THE BAHAMAS AND CUBA DURING TODAY THROUGH SAT. AS THIS AREA OF UNSETTLED WEATHER SPREADS E...THE RIDGE WILL RETREAT TO E OF THE AREA BY FRI AFTERNOON. GLOBAL MODELS CONTINUE TO KEY ON A TROUGH FEATURE WITH A SUBSEQUENT LOW MATERIALIZING JUST E OF THE BAHAMAS DURING THIS FORECAST CYCLE. AS UPPER DYNAMICS ASSOCIATED WITH THE MID/UPPER TROUGH IN THE GULF OF MEXICO SHIFT EASTWARD TO THE WESTERN PORTION OF THE ATLC OVER THE NEXT 48 HOURS...THAT IS WHAT SHOULD THEN SPIN UP A LOW ON THE E SIDE OF THE BAHAMAS AS MODELS PORTRAY. MODELS DIFFER TO SOME EXTENT WITH EVENTUALLY EVOLUTION AND MOVEMENT OF THIS FEATURE FOR THE LATTER DAYS OF THE THIS FORECAST. BOTH GFS AND EUROPEAN LIKE THE LOW SCENARIO STARTING JUST E OF THE NORTHERN BAHAMAS SOMETIME LATE TONIGHT WITH EUROPEAN TAKING IT NE THEN N TO JUST N OF THE AREA BY LATE MON. THE GFS IS SLIGHTER SLOWER THAN THE EUROPEAN...AND SIMILAR TO THE NOGAPS IN TIMING. IT TAKES KING ONE LOW E TO NEAR 28N71W BY LATE SUN...AND TO NEAR 31N73W BY LATE MON. IT TAKES ANOTHER LOW SSE NEAR THE SE BAHAMAS SAT INTO SUN THEN DISSIPATES IT. UKMET AND CANADIAN JUST HANG ON TO A TROUGH THROUGH MON. IN GENERAL...ALL MODELS DEPICT THAT A LOW PRES TROUGH WILL BE NEAR THE VICINITY OF THE BAHAMAS THROUGH MON. THE MAIN THING WITH THIS SCENARIO WILL NOT SOME MUCH THAT A LOW SHOULD FORM...BUT THAT THE SQUEEZE PLAY THAT WILL TAKE PLACE BETWEEN THE TROUGH/LOW AND THE RIDGE TO THE E OF THE AREA. THIS SHOULD LEAD TO AN INCREASING PRES GRADIENT OVER THE NE AND E PORTIONS BEGINNING ON FRI AND THROUGH SUN WITH INDICATIONS OF ELY WINDS IN THE 20-25 KT WITH THE POSSIBILITY OF GALE WINDS LATE SAT IN THE NE WATERS. CARIBBEAN AND TROPICAL N ATLC... WITH THE ATLC RIDGE BEING RATHER WEAK AS IT MIGRATES EASTWARD...WINDS THROUGHOUT ARE LIGHTER THAN IN PREVIOUS DAYS. AN ASCAT PASS FROM NEAR 0128 UTC LAST NIGHT SHOWED A POCKET OF E 20-25 KT WINDS S OF 14N BETWEEN 68W-72W. E WINDS OF 15-20 KT ARE CONFINE TO A STRIP IN THE TROPICAL N ATLC N OF ABOUT 14N. THESE WINDS SHOULD DIMINISH TO 10-15 KT ON SAT. 0600 UTC SEASTATE ANALYSIS SHOWED THAT SEAS IN THE 6-8 FT RANGE THROUGHOUT THE TROPICAL N ATLC WITH SEAS UP TO 10 FT IN THE FAR SW CARIBBEAN SEA NEAR THE COLOMBIAN COAST. A LOW LATITUDE TROPICAL WAVE CURRENTLY WELL E OF THE AREA MAY APPROACH THE FAR SE TROPICAL N ATLC IN ABOUT 36 HOURS. MODELS HINT AT WEAK TROUGH OR LOW DEVELOPING THE FAR SW CARIBBEAN SEA OVER THE NEXT FEW DAYS. WILL ANALYZE FUTURE MODEL FOR MORE CONSISTENCY WITH THIS FEATURE BEFORE DETAILING IT TO MUCH IN THE FORECAST. WARNINGS... ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE